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Quick ASA question - Vision 2 negative film


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#1 Bjarne Eldhuset

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Posted 23 September 2006 - 02:14 PM

I'm a bit confused, so I'll ask you who follow Non-Confusius instead:

1. At which asa does the nizo professional read the vision 2 500t? Is it at 320? Some say 640, some say 320.
2. At which asa does the Nikon R10 read the vision 2 500t? Some say at 400, others at 640. I need to know so I can set my external meter correctly, as the internal meter isn't working.

Again, thanks for all your help so far! Hope someone will bare with my basic questions for a little while longer :-)

Regards, Bjarne Eldhuset, Oslo, Norway.
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#2 Matthew W. Phillips

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Posted 24 September 2006 - 07:39 PM

I'm a bit confused, so I'll ask you who follow Non-Confusius instead:

1. At which asa does the nizo professional read the vision 2 500t? Is it at 320? Some say 640, some say 320.
2. At which asa does the Nikon R10 read the vision 2 500t? Some say at 400, others at 640. I need to know so I can set my external meter correctly, as the internal meter isn't working.

Again, thanks for all your help so far! Hope someone will bare with my basic questions for a little while longer :-)

Regards, Bjarne Eldhuset, Oslo, Norway.


Ok, Im a bit confused about your question. If you are using external meter, Im assuming you have manual exposure right? And if you have manual exposure and external meter, why does it matter what the Nizo thinks the film is? You just plug into your meter what speed your film is, the shutter speed, and gauge the available light and you get your exposure. It really doesnt matter what the camera thinks the film speed is if you use manual exposure and external meter.
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#3 Mike Rizos

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Posted 24 September 2006 - 08:04 PM

Right, since the meter is not working it just use your handheld meter and rate it 320 or 400 for slight overexposure.
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#4 Mike Rizos

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Posted 24 September 2006 - 08:17 PM

I forgot to add that you also need to compansate for the beamsplitter, another 1/4-1/3 of a stop.
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#5 Matthew W. Phillips

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Posted 25 September 2006 - 11:21 PM

I forgot to add that you also need to compansate for the beamsplitter, another 1/4-1/3 of a stop.


Yeah, definitely dont forget this one. On color neg, its not such a big deal. But if you shoot on reversal, this one can doom your footage if you dont compensate.
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#6 ben jones

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Posted 26 September 2006 - 12:54 PM

Hello all.

I have a similar question - about to shoot a music video with a braun Nizo s56. Im shooting on vision 2 500T using manual exposure, and mostly interior. I have been told to rate the stock at 400 asa to compensate for the stop loss from the beam splitter. If I were to then shoot exterior, what would I now rate the asa at?

Also, would anyone be kind enough to give me the asa ratings if I were to shoot 200T in the above conditions?

thanks - Ben :lol:
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#7 Jonathan Benny

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Posted 26 September 2006 - 06:11 PM

about to shoot a music video with a braun Nizo s56. Im shooting on vision 2 500T using manual exposure, and mostly interior. I have been told to rate the stock at 400 asa to compensate for the stop loss from the beam splitter. If I were to then shoot exterior, what would I now rate the asa at?

Also, would anyone be kind enough to give me the asa ratings if I were to shoot 200T in the above conditions?


The quick answer to your questions are:

If you are rating the stock at 400 tungsten balance (implies interior) then when you go outside and put an 85 on the lens, you need to compensate another 2/3rds of a stop which would bring you to 250ASA.

If you started with 200T, then you take away 1/3 of a stop to get 160 (for that viewing system), then, another 2/3rds for that 85 you are using outside which will bring you to 100ASA.

I'm not sure how your camera works. If you have a built in switch that says "daylight", then it probably has the filter built in internally. You're doing manual exposure, so you would still have to manually change the setting on your own light meter. The meter in the camera might automatically make the compensation on its own. Check that.

Now: you can easily answer these questions yourself if you do the following:

Memorize the sequence of the following numbers.

25, 32, 40, 50, 64, 80, 100, 125, 160, 200, 250, 320, 400, 500, 640, 800, 1000

These are the sequence of ASA. They run in 1/3 stop increments.

80 is 1/3 stop slower than 100.
200 is 1 stop faster than 100.

When you want to figure out where to set your meter when you are making compensations do the following:

Read what the recommended EI (ASA) rating of the film is. Lets take 5218 as an example.

5218 has a rec ei of 500 (asa) and is TUNGSTEN balanced.

If you go outside, unless you are going for a particular effect, you will need to put an 85 filter on the lens (assuming it is not built into your camera) because DAYLIGHT will record abnormally bluish.

An 85 filter absorbs the equiv of 2/3rds of a stop of light.

Now go back to that sequence of numbers. When making compensations you go to a LOWER number to compensate for light that has been lost as a result of a filter.

So, if the 85 absorbs 2/3rds of a stop, and each number on that asa scale represents 1/3rd of a stop. Where are you going to end up if you started at 500?

The answer is 320.

Then, if you need to do another 1/3rd of a stop for your camera's viewing system. Where do you end up?

The answer is 250.

Just start with the original rating of the film and work from there. Input your final ASA rating, after compensations, into your meter and it will then give you the compensated stop when you take a reading.

Make sure that you know whether the negative is daylight balanced or tungsten balanced (in your case, Vision2 500 is tungsten balanced). If you were using a daylight balanced film, like 01, you would not need an 85 filter outside, but then, inside, if you were using tunsgsten lights, things would look "too" orange.

Make sure that your viewing system in fact absorbs 1/3rd of a stop of light and whether or not the camera has its own built in 85 filter that can be engaged when shooting outdoors.

AJB
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#8 Matthew W. Phillips

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Posted 26 September 2006 - 06:19 PM

If you were using a daylight balanced film, like 01, you would not need an 85 filter outside, but then, inside, if you were using tunsgsten lights, things would look "too" orange.


Yeah, and you can correct this with an 80A filter.
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#9 Jonathan Benny

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Posted 26 September 2006 - 06:30 PM

Yeah, and you can correct this with an 80A filter.


True. But very rare. The filter factor is too great for most applications.

AJB
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#10 ben jones

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Posted 27 September 2006 - 07:03 AM

Dear Jonathan.

Thankyou for you reply and infomation - you have helped me enormously. I will use this system from now on.

kind regards Ben Jones.
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#11 Matthew W. Phillips

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Posted 27 September 2006 - 07:42 AM

The quick answer to your questions are:

If you are rating the stock at 400 tungsten balance (implies interior) then when you go outside and put an 85 on the lens, you need to compensate another 2/3rds of a stop which would bring you to 250ASA.

If you started with 200T, then you take away 1/3 of a stop to get 160 (for that viewing system), then, another 2/3rds for that 85 you are using outside which will bring you to 100ASA.

I'm not sure how your camera works. If you have a built in switch that says "daylight", then it probably has the filter built in internally. You're doing manual exposure, so you would still have to manually change the setting on your own light meter. The meter in the camera might automatically make the compensation on its own. Check that.

Now: you can easily answer these questions yourself if you do the following:

Memorize the sequence of the following numbers.

25, 32, 40, 50, 64, 80, 100, 125, 160, 200, 250, 320, 400, 500, 640, 800, 1000

These are the sequence of ASA. They run in 1/3 stop increments.

80 is 1/3 stop slower than 100.
200 is 1 stop faster than 100.

When you want to figure out where to set your meter when you are making compensations do the following:

Read what the recommended EI (ASA) rating of the film is. Lets take 5218 as an example.

5218 has a rec ei of 500 (asa) and is TUNGSTEN balanced.

If you go outside, unless you are going for a particular effect, you will need to put an 85 filter on the lens (assuming it is not built into your camera) because DAYLIGHT will record abnormally bluish.

An 85 filter absorbs the equiv of 2/3rds of a stop of light.

Now go back to that sequence of numbers. When making compensations you go to a LOWER number to compensate for light that has been lost as a result of a filter.

So, if the 85 absorbs 2/3rds of a stop, and each number on that asa scale represents 1/3rd of a stop. Where are you going to end up if you started at 500?

The answer is 320.

Then, if you need to do another 1/3rd of a stop for your camera's viewing system. Where do you end up?

The answer is 250.

Just start with the original rating of the film and work from there. Input your final ASA rating, after compensations, into your meter and it will then give you the compensated stop when you take a reading.

Make sure that you know whether the negative is daylight balanced or tungsten balanced (in your case, Vision2 500 is tungsten balanced). If you were using a daylight balanced film, like 01, you would not need an 85 filter outside, but then, inside, if you were using tunsgsten lights, things would look "too" orange.

Make sure that your viewing system in fact absorbs 1/3rd of a stop of light and whether or not the camera has its own built in 85 filter that can be engaged when shooting outdoors.

AJB


That was a mouthful. I personally had great results (with reversal) with just dialing the ISO, shutter speed, and measuring the light with an incident meter and adding a 1/3 of a stop to my exposure. This here sounds
complicated. I never realized I was doing it wrong.
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#12 David W Scott

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Posted 27 September 2006 - 08:39 AM

That was a mouthful. I personally had great results (with reversal) with just dialing the ISO, shutter speed, and measuring the light with an incident meter and adding a 1/3 of a stop to my exposure. This here sounds
complicated. I never realized I was doing it wrong.


He's doing basically the same thing. Just a few more words to explain it! But it's the kind of explanation that really clarifies things, especially for folks who aren't conversant in stops.

The only difference between his technique and yours is he compensates once, on the meter, and you compensate every time, on your aperture.
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#13 Jonathan Benny

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Posted 27 September 2006 - 09:17 AM

I personally had great results (with reversal) with just dialing the ISO, shutter speed, and measuring the light with an incident meter and adding a 1/3 of a stop to my exposure. This here sounds
complicated. I never realized I was doing it wrong.


His question was "what would I now rate the asa at?". Its important to know how to do this because when you get into more sophisticated filter combinations that are mixed into other factors it can be nice to be able to simply dial in a new EI number into the meter for a given scene.

For example:

If I'm shooting on 5217 with an 85, 1/4 coral, I'm bleach bypassing the neg (so I'm going to underexpose by 1 stop based on the tests), and I'm shooting at 48fps: what would the asa be that I would want to program into the meter?

For me, over a number of setups, it is easier to simply calculate the resulting "asa" before I start shooting and use that on the meter for the whole scene/setup. Its not complicated at all. In situations, where, say we want to slide in an ND filter at the last minute or change frame rates at the last minute, then yes, I would simply make the compensation on the lens and not worry about the meter. But in most cases, certainly, it makes sense to program your meter with "320" asa as opposed to "500" asa if you're shooting exterior on 5218 with an 85 - and if you like to give another 1/3 of a stop (like I do), then you put "250" into the meter. The issue is how do you come up with the number "250"? That was the question I was answering.

Nobody said anything about your system being wrong. But the question was related to asa numbers.

Another big reason for using ASA numbers rather than doing the compensation at the last minute is if I am going for a specific stop on the lens for dof purposes or continuity, its a lot easier to target a particular stop based on all filter factors and other compensations already programmed into the meter.

By the way: the answer to my example is: 100

AJB
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#14 Sean McHenry

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Posted 29 September 2006 - 04:06 PM

Hey all,
In my case, using a Canon 814, could I simply figure, if using 500T outside, lose 1/3 stop (takes me to ASA 400) and add 2/3 f-stop (down to 250 ASA now) manually to whatever the internal meter tells me I should be set at? Seems easy enough to remember that way.

That is, if the internal meter is telling me to shoot f5.6 for given daylight conditions with the filter in place, just add 2/3 stop for a real stop of just under f8 (or there abouts)? Reason for all this is that the Canon 814 only recognizes up to 250 as I recall from the manual.

I am trying to squeek out some nice shots at dusk in a graveyard for a short (and no, this one's not a horror flic). If anyone has other suggestions for shooting with the Canon 814 or similar series (looking at a 1014 on ebay), I welcome e-mails on this one. McHenryProj@yahoo.com

While I have you here, recommendations on TC from 500T negative stock to DVCam?

Thanks all,

Sean McHenry
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